Regensburg 2010 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 36: Posters: Tissue Dynamics, Charge Effects, and Anomalous Transport
BP 36.5: Poster
Donnerstag, 25. März 2010, 17:15–20:00, Poster B2
Simulation and analysis of neuronal pattern formation in the visual cortex — •Ghazaleh Afshar1,2, Dominik Heide5, Lars Reichl1,2, and Fred Wolf1,2,3,4 — 1MPIDS, Göttingen — 2BCCN, Göttingen — 3Georg-August-Universität, Göttingen — 4IMPRS, Göttingen — 5FIAS, Frankfurt am Main
Orientation preference maps in the visual cortex, characterized by topological point defects called pinwheels, presumably develop by self-organization of neuronal circuits [1,2]. It was shown recently that the spacing of adjacent orientation columns exhibits a high degree of variability within the visual cortex [3]. We generalized a model based on Turing type instability proposed previously [1] to exhibit a map of local column spacing instead of a single fixed wavelength and studied this model numerically. In the homogeneous model defect densities of solutions split at a late stage of development filling a broad band of values. In the model with spacing heterogeneity this splitting is suppressed. In contrast to the homogeneous model in which the power spectrum of the stable solutions is composed of a finite number of Fourier components, in the heterogeneous model the power spectrum asymptotically shows a continuous band of modes around the critical circle with a finite width depending on the strength of spacing inhomogeneity. This closely resembles the experimental observation. We conclude that wavelength heterogeneity substantially increases the agreement between experimental observation and Turing type models of neural pattern formation. [1] Wolf. PRL (2005). [2] Kaschube et al. NJP (2008). [3] Kaschube et al. PNAS (2009).